scholarly journals Determination of the corresponding roughness height in a WDS model containing old rough pipes

2019 ◽  
Vol 69 (3) ◽  
pp. 201-209 ◽  
Author(s):  
Ivar Annus ◽  
Anatoli Vassiljev ◽  
Nils Kändler ◽  
Katrin Kaur
Keyword(s):  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Pipe Wall ◽  
Field Studies ◽  
Quality Estimation ◽  
Pipe Surface ◽  
Computational Fluid Dynamics Cfd ◽  
The Mean

Abstract The aim of the paper was to determine the influence of irregular pipe wall roughness on the flow velocity in a water distribution system (WDS) containing old pipes. Field studies have shown that due to pipe wall build-up, the shape of the inner pipe surface can vary temporally and spatially. This will lead to unrealistic pipe roughness values when calibrating the WDS model using nominal pipe diameters. Therefore, in this study, three types of pipe wall build-up were investigated using EPANET2 and computational fluid dynamics (CFD) to estimate the velocity correction coefficients for EPANET2 calculations. It was shown that in old rough pipes, the mean velocities are higher than expected, indicating that in water quality estimation in a WDS, actual pipe diameters with reasonable roughness need to be defined.

scholarly journals Ranking Approach to Scheduling Repairs of a Water Distribution System for the Post-Disaster Response and Restoration Service

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1591 ◽  
Author(s):  
Bałut ◽  
Brodziak ◽  
Bylka ◽  
Zakrzewski
Keyword(s):  
Distribution System ◽  
Disaster Response ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Preference Ranking ◽  
Task List ◽  
Sequencing Method ◽  
Post Disaster

: On the maintenance task list of each water distribution system (WDS) operator, determination of the order of undertaken repairs seems quite a typical task. Characteristics of damages, their localization, and other factors that influence repair sequencing have a sound impact on the execution of such tasks. In the case of the most complex cases where numerous failures of different types occur at the very same time (i.e., due to earthquakes), there is a long list of selection criteria that have to be analyzed to deliver an objectively logical schedule for repair teams. In this article, authors attempt to find out if it is possible to define pipe rankings in having obtained the best factors for defined objective functions (criteria), making it feasible to deliver judicious repair sequencing. For the purposes of this paper, a survey has been carried out. Its conclusions made it possible to propose a method to create rankings of pipes and evaluate them using a selected multicriteria decision method: preference ranking organization method for enrichment evaluation (PROMETHEE). The work was carried out for five different disaster scenarios that had been supplied by ‘The Battle of Post-Disaster Response and Restoration’ organization committee. Obtained results might be further used to finetune this sequencing method of undertaken repairs, while conclusions could be useful to model similar events in WDS when required. This article is an extended paper based on the conference preprint presented at the 1st International Water Distribution Systems Analysis (WDSA)/International Computing & Control for the Water Industry (CCWI) Joint Conference in July 23–25, 2018 in Kingston, Ontario, Canada.

scholarly journals The Interaction between the Bulking Water and Pipe Surface and Their Correlations in Water Distribution System

2018 ◽  
Vol 7 (2) ◽  
pp. 83
Author(s):  
Ruilian Li ◽  
Ming-qing Feng ◽  
Xiao-hui Bai
Keyword(s):  
Water Quality ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Tap Water ◽  
Close Relation ◽  
Quality Parameters ◽  
Iron Corrosion ◽  
Pipe Surface ◽  
Pipe Water

The pipelines corrosion can result discolor and particle increase in tap water and the complaints from the consumers. It also has the economic and hydraulic impacts for the replacement of broken pipes and fouling of corroded pipes. This paper aimed to investigate the effect of processed drinking water on metal pipe corrosion in water distribution system and the relations between the bulking water quality and pipe corrosion. It was found that there is a close relation between iron corrosion and water quality parameters in water distribution pipelines. It was shown that lower pH and alkalinity can increase the corrosion rate, while higher chlorides and sulfate may cause pitting corrosion. DOC in pipe water would be beneficial for microbial induced corrosion.

scholarly journals Numerical investigation of the impact of irregular pipe wall build-up on velocity in the water distribution system

2020 ◽  
Vol 69 (7) ◽  
pp. 647-655
Author(s):  
Katrin Kaur ◽  
Anatoli Vassiljev ◽  
Ivar Annus ◽  
Nils Kändler ◽  
Janet Roosimägi
Keyword(s):  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Pipe Wall ◽  
Propagation Rate ◽  
Flow Section ◽  
Surface Geometry ◽  
Velocity Correction ◽  
Real Flow ◽  
The Impact

Abstract This paper presents novel equations for different wall build-up types in old pipes developed for the estimation of real flow velocities in a water distribution system (WDS). This is important when estimating the contamination propagation rate in an operational WDS. Because the inner surface geometry of old rough pipes is complex, real velocities cannot be estimated by conventional WDS models. Therefore, a computational fluid dynamics (CFD) model was used to analyse the flow dynamics in old rough pipes with even and uneven roughness build-up. The developed equations for the velocity correction coefficients derive from the results of numerical simulations. Numerically obtained velocity fields show that in some cases, pipe wall build-up can affect the effective flow section significantly and the flow velocity can be underestimated by more than two times. Therefore, different velocity correction equations have to be used for different types of pipe wall build-up.

scholarly journals Detecting Pipe Wall Biofilms in Water Distribution System

2011 ◽  
Vol 11 ◽  
pp. 3085-3090
Author(s):  
Shu Shihu ◽  
Zhang Dong ◽  
Wu Yuxin
Keyword(s):  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Pipe Wall
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